Many kinds of removable band-type couplings for pipes exist in the art. It is noted that throughout the specification and claims, the term “pipe” encompasses any kind of generally cylindrical object.
US Patent Application 20070273151 to the present inventors, filed on 15 Feb. 2007, the disclosure of which is incorporated herein by reference, describes an improvement on a cast flange for pipe couplings. The improved flange and its seal are attachable to the external surface of a pipe and can be used to eliminate a small leak if access to a pipe extremity is available. Clamp members are positioned face to face and a tightening element is tightened to press an annular seal element against the outside of the pipe inserted through the seal clamp housing. The annular seal element returns to its original dimensions after release of the tightening element.